xfs quota does not work with encrypted loop filesystem

[Ying-Hung Chen <ying@xxxxxxxxxxxxxx>]

Hi,

        I am currently running mandrake 9.2, (this applies to 9.1 and 9.0 also)

xfs quota does not work with encrypted option turned on. (through the 
loop device)
for example:

/dev/hde11 /home xfs encryption=AES128,encrypted,grpquota,usrquota 0 0

has the encryption, but unable to assign quota, enforce or show quota.

without the encryption, quota just works.

I believe this is probably not mandrake specific problem, does anyone 
have similar setup that works?
Thanks,

-Ying

PS. Please CC me on reply.